While certainly part of the problem, I think consumers not being able to buy a decent $500-$600 ultrabook, or a touchscreen laptop without paying $100-$200 more than for exactly the same non-touch model should also not be discounted. Also the PC market was in a major decline before Windows 8 was released. I'm not sure how something failing to turn a sinking ship around is to blame for sinking the ship in the first place.
Obviously simply getting rid of Sinofsky isn't going to be the supreme solution that will revitalize interest in Windows and the PC market, nor will getting rid of metro, getting rid of the desktop, or making more shiny machines at premium prices. The root of the problem is complex, and the solution is unlikely to come from forum post wisdom.